Hi,
I am writing about, How do prevent other people's music being copied to your iPod? As I mean by that is I have to share my computer because my brother has an iPod account on that also. So we have to use the same itunes account. Whenever I put new songs on my iPod my brother's and cousin songs get copied to it also. So how do I prevent that?

When you connect your iPod, go into iTunes, click your iPod, then in these tabs there should be an option to "Manually add/remove songs."

The other possibility is to setup multiple user accounts for the operating system. This option is a little bit more involved. But it would still allow for automatic synchronizing without meshing the libraries together.